drivers/leds/leds-s3c24xx.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* drivers/leds/leds-s3c24xx.c
   3  *
   4  * (c) 2006 Simtec Electronics
   5  *      http://armlinux.simtec.co.uk/
   6  *      Ben Dooks <ben@simtec.co.uk>
   7  *
   8  * S3C24XX - LEDs GPIO driver
   9 */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/leds.h>
  14 #include <linux/gpio.h>
  15 #include <linux/slab.h>
  16 #include <linux/module.h>
  17 #include <linux/platform_data/leds-s3c24xx.h>
  18
  19 #include <mach/regs-gpio.h>
  20 #include <plat/gpio-cfg.h>
  21
  22 /* our context */
  23
  24 struct s3c24xx_gpio_led {
  25         struct led_classdev              cdev;
  26         struct s3c24xx_led_platdata     *pdata;
  27 };
  28
  29 static inline struct s3c24xx_gpio_led *to_gpio(struct led_classdev *led_cdev)
  30 {
  31         return container_of(led_cdev, struct s3c24xx_gpio_led, cdev);
  32 }
  33
  34 static void s3c24xx_led_set(struct led_classdev *led_cdev,
  35                             enum led_brightness value)
  36 {
  37         struct s3c24xx_gpio_led *led = to_gpio(led_cdev);
  38         struct s3c24xx_led_platdata *pd = led->pdata;
  39         int state = (value ? 1 : 0) ^ (pd->flags & S3C24XX_LEDF_ACTLOW);
  40
  41         /* there will be a short delay between setting the output and
  42          * going from output to input when using tristate. */
  43
  44         gpio_set_value(pd->gpio, state);
  45
  46         if (pd->flags & S3C24XX_LEDF_TRISTATE) {
  47                 if (value)
  48                         gpio_direction_output(pd->gpio, state);
  49                 else
  50                         gpio_direction_input(pd->gpio);
  51         }
  52 }
  53
  54 static int s3c24xx_led_probe(struct platform_device *dev)
  55 {
  56         struct s3c24xx_led_platdata *pdata = dev_get_platdata(&dev->dev);
  57         struct s3c24xx_gpio_led *led;
  58         int ret;
  59
  60         led = devm_kzalloc(&dev->dev, sizeof(struct s3c24xx_gpio_led),
  61                            GFP_KERNEL);
  62         if (!led)
  63                 return -ENOMEM;
  64
  65         led->cdev.brightness_set = s3c24xx_led_set;
  66         led->cdev.default_trigger = pdata->def_trigger;
  67         led->cdev.name = pdata->name;
  68         led->cdev.flags |= LED_CORE_SUSPENDRESUME;
  69
  70         led->pdata = pdata;
  71
  72         ret = devm_gpio_request(&dev->dev, pdata->gpio, "S3C24XX_LED");
  73         if (ret < 0)
  74                 return ret;
  75
  76         /* no point in having a pull-up if we are always driving */
  77
  78         s3c_gpio_setpull(pdata->gpio, S3C_GPIO_PULL_NONE);
  79
  80         if (pdata->flags & S3C24XX_LEDF_TRISTATE)
  81                 gpio_direction_input(pdata->gpio);
  82         else
  83                 gpio_direction_output(pdata->gpio,
  84                         pdata->flags & S3C24XX_LEDF_ACTLOW ? 1 : 0);
  85
  86         /* register our new led device */
  87
  88         ret = devm_led_classdev_register(&dev->dev, &led->cdev);
  89         if (ret < 0)
  90                 dev_err(&dev->dev, "led_classdev_register failed\n");
  91
  92         return ret;
  93 }
  94
  95 static struct platform_driver s3c24xx_led_driver = {
  96         .probe          = s3c24xx_led_probe,
  97         .driver         = {
  98                 .name           = "s3c24xx_led",
  99         },
 100 };
 101
 102 module_platform_driver(s3c24xx_led_driver);
 103
 104 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 105 MODULE_DESCRIPTION("S3C24XX LED driver");
 106 MODULE_LICENSE("GPL");
 107 MODULE_ALIAS("platform:s3c24xx_led");